But now tenants are demanding they have agile workplaces, high quality end of trip facilities and sustainable green-star credentials.

There is alsoa new wave of offering hotel concierge services in an office tower.

One of the latest to offer a range of these "must haves" is the Far East Organisation's 227 Elizabeth Street, a 24-level commercial tower in Sydney's CBD which has tenants flocking to the asset in a bid to secure newly fitted-out space in a tightening market.

According to the agents at Colliers International, 11 leases have been signed since the start of 2016 with another eight leases signed in the last half of 2015, with record rents achieved for the B grade asset. These have been through Jock Gilchrist and Tom Buxton of Colliers International.

The agents said 227 Elizabeth Street that with office areas ranging from about 85sq m to 900sq m, rental figures range from $725 to $890 with 2016 tenants including: Harmony, Jindu, Ekornes, Boardroom.Media, Prime Development, Royale Wealth & Partners, Ullink, Evergrand, Better Homes, Liferay and Menulog; all on long lease terms.

But with the office market continuously evolving to accommodate the demands of a 21st-century workforce, there are a few trends affecting investors and office occupiers alike.

According to Cameron Williams, national director of office leasing for Colliers International, asset optimisation is the new sustainability when tenants look to lease.

Mr Williams said environmental impact was simply one cog in a very large wheel of holistic building management that experienced commercial property managers brought to the table.

"In addition to looking at the presentation and performance of their property, smart landlords are looking to their property managers for a holistic approach to asset optimisation," he said.

"Risk mitigation, operating efficiencies, innovative tenant retention, real-time financial management, additional income opportunities, 'wellness' offerings, benchmarking analysis, procurement and customer service are just some of the strategies being incorporated to not only make assets perform at their best but deliver the services and facilities their tenants desire."

According to Simon Crouch, national head of tenant advisory for Colliers International, an increase in demand for office space from corporate occupiers in Sydney and Melbourne indicates that more challenging times may be ahead for corporate tenants in these markets.

"It's important for occupiers to be informed and have a well thought out workplace and property strategy to secure the best accommodation solution," Mr Crouch said.

"This requires a deep understanding of market conditions and trends to identify and mitigate risk, and to uncover and take advantage of opportunities."

Colliers International's research also shows that average workplace densities have declined from 27sq m per person in 1992 to 15sq m per person in 2015. This trend is being driven by the demand from organisations to derive more and more efficiencies from their office accommodation.

"Financial institutions are typically heading well below 10sq m per person on typical floor, while law firms are targeting between 12 and 18sq m per person," Mr Williams said.

"Before a plan is devised to move to a new way of working, it's important to have clearly defined goals, an understanding of work and occupancy patterns and an evidence-based workplace strategy that aligns people, technology and workplace to drive change."

Offering five-star hotel services has also arrived within offices, according to Peter Black, national director, workplace strategy and design for Colliers International.

"The edges have blurred between where we work, live and play, so much so that we no longer have just one place for each part of our life," he said. "We live, work and play at home and at work.

"Blurring the edges also means workspaces now need to support workers with hospitality-style services such as concierge, front-of-house help-desk, quality end of trip facilities and 'wellness' options that support their health, wellbeing and busy lives, increasing employee happiness and productivity.

"Premium corporate occupiers are realising that as agile work practices surge in popularity, so too does the need to provide flexible, high-performing office environments that create and support communities – spaces that allow people to connect and collaborate."